Fig. 8: Graphical summary.

Both alloantigen-specific and polyclonal donor Treg expansion protocols generate functional cells that acquire organ-specific gene expression profiles in vivo upon transfer. In addition, both types of expanded Tregs induce genes involved in the suppression of conventional donor T cells (inhibitory cytokines, genes involved in metabolic disruption and cytotoxic genes) and ameliorate GvHD symptoms. The major difference between alloantigen-specific and polyclonal donor Treg is their different TCR repertoire ex vivo and in vivo after transplant, which may contribute to the initial therapeutic benefit and survival advantage of alloantigen-specific Treg.